2 Syllables: SU
bias, blindness, brightens, brightest, brightness, Byron's, childless, China's, crisis, diamonds, driest, dryness, finest, frightens, guileless, guises, heightens, highest, Highlands, Highness, hybrids, ibis, ices, Isis, islands, items, kindest, kindness, lias, lichens, lifeless, lightest, lightness, likeness, lions, liveliest, Lyons, mightiest, mildest, mildness, mileage, minus, pious, Pius, priceless, prices, primus, prius, prizes, righteous, ripeness, ripens, rises, shyness, Silas, Simon's, sinus, sirens, sizes, slices, slightest, spices, tightness, timeless, tiniest, Titans, Titus, typhus, viands, vices, whiteness, widens, widest, wildness, wisest
2 Syllables: US
3 Syllables: USU
advices, Aquinas, arthritis, asylums, bronchitis, comprises, Darius, devices, Elias, environs, Goliath, horizons, impious, Matthias, politeness, Tobias, unbiased, unbiassed, unkindness, unrighteous, uprightness
4 Syllables: UUSU
Found 100 words across 4 groupings. Skipped 2 excess words of a similar stem.